Many battery-powered devices such as, for example, mobile phones or electronic notebooks contain complex integrated circuits powered by one or more supply voltages. These supply voltages are often generated from a battery voltage by voltage regulators integrated in semiconductor circuits. One type of linear voltage regulator is the low drop out voltage regulator (“LDO”). An LDO is capable of furnishing a stable regulated voltage even when the difference between the battery voltage and the desired supply voltage is very small. Consequently, the battery voltage may be only insignificantly higher than the desired output voltage and as a rule the dissipation loss of the LDO is very low. Thus, the LDO is capable of stabilizing the supply voltage even when the battery voltage has been greatly reduced due to discharge.
The various circuits to which an LDO supplies voltage may have several different operational modes, with each mode presenting a different load to the regulator. As the circuit changes modes, the load presented to the regulator can rapidly change. Rapid load changes can result in generation of transients at the regulator output. Generally, power supply voltage transients are to be avoided. Consequently, improved LDO load transient response is desirable.